Phenotype-specific determinants of health-related quality of life in Crohn's disease and ulcerative colitis: a multicenter cross-sectional study.

BACKGROUND

Health-related quality of life (HRQoL) is central to the management of inflammatory bowel disease (IBD), including Crohn's disease (CD) and ulcerative colitis (UC), yet domain-specific determinants remain underdefined in real-world settings. We aimed to identify phenotype-specific determinants of total and domain-level HRQoL in a real-world Palestinian cohort of patients with CD and UC.

METHODS

We performed a multicenter cross-sectional study (December 2018-June 2024) across eight governmental hospitals in the Palestinian West Bank. Adults with Crohn's disease (CD) or ulcerative colitis (UC) were enrolled consecutively (N = 301; CD n = 219, UC n = 82). We measured health-related quality of life (HRQoL) using the Short Inflammatory Bowel Disease Questionnaire (SIBDQ). We used multivariable linear regression, stratified by phenotype (CD/UC), to model total and domain-level SIBDQ scores. Candidate predictors included prespecified clinical, laboratory, imaging, and treatment-related variables.

RESULTS

UC patients were older (median 39.5 vs. 35 years) and less often male (47.6% vs. 62.6%); CD showed more structural disease (stenosis 55.7% vs. 26.8%) and surgery (31.5% vs. 13.4%). Baseline fecal calprotectin (FC) > 1000 µg/g was more frequent in UC (50.0% vs. 37.9%). In Crohn's disease, impaired HRQoL was primarily driven by ongoing inflammation and structural disease. Lower Total SIBDQ scores were independently associated with higher fecal calprotectin at 3 months (aβ - 1.235) and a positive comb sign (aβ - 4.162), while clinical remission was strongly protective (aβ + 4.549). Key domain effects included worse Bowel scores with infliximab use (aβ - 1.162), worse Systemic scores with higher FC-3 m (aβ - 0.411), and worse Emotional scores with smoking (aβ - 1.245) and higher FC-3 m (aβ - 0.671). In ulcerative colitis, reduced HRQoL was dominated by structural involvement and treatment burden. Lower Total SIBDQ scores were associated with a positive comb sign (aβ - 5.419) and longer therapy duration (aβ - 0.052). Domain-level impairment was most evident in worse Social scores with hypertension (aβ - 3.731) and worse Emotional scores with smoking (aβ - 3.001) and higher FC-3 m (aβ - 0.722).

CONCLUSIONS

In this multicenter cross-sectional cohort, correlates of HRQoL differed between Crohn's disease and ulcerative colitis, and objective inflammatory activity, imaging findings, treatment exposure, and modifiable factors showed domain-specific associations with SIBDQ scores. Because temporality cannot be established, these findings should be interpreted as associations rather than causal effects. Nonetheless, they support integrating FC-3 m and cross-sectional imaging markers into HRQoL-guided treat-to-target decisions in routine care and underscore the need for longitudinal studies to validate these phenotype-specific determinants over time.